diff --git a/include/picrin.h b/include/picrin.h
index 08f01796..b34012b7 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -33,6 +33,8 @@ extern "C" {
 #include <setjmp.h>
 #include <stdio.h>
 
+#include "xhash/xhash.h"
+
 #if __STDC_VERSION__ >= 201112L
 # define NORETURN _Noreturn
 #elif __GNUC__ || __clang__
diff --git a/src/codegen.c b/src/codegen.c
index 9352807f..93bf5556 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -11,7 +11,6 @@
 #include "picrin/proc.h"
 #include "picrin/lib.h"
 #include "picrin/macro.h"
-#include "xhash/xhash.h"
 
 #if PIC_NONE_IS_FALSE
 # define OP_PUSHNONE OP_PUSHFALSE
diff --git a/src/gc.c b/src/gc.c
index bab5505f..8bdd10e0 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -15,7 +15,6 @@
 #include "picrin/macro.h"
 #include "picrin/lib.h"
 #include "picrin/var.h"
-#include "xhash/xhash.h"
 
 #if GC_DEBUG
 # include <string.h>
diff --git a/src/init.c b/src/init.c
index de8c2bb6..c2b9fdf6 100644
--- a/src/init.c
+++ b/src/init.c
@@ -9,7 +9,6 @@
 #include "picrin/pair.h"
 #include "picrin/lib.h"
 #include "picrin/macro.h"
-#include "xhash/xhash.h"
 
 void pic_init_bool(pic_state *);
 void pic_init_pair(pic_state *);
diff --git a/src/lib.c b/src/lib.c
index de47cae2..90e5419a 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -6,7 +6,6 @@
 #include "picrin/lib.h"
 #include "picrin/pair.h"
 #include "picrin/macro.h"
-#include "xhash/xhash.h"
 
 struct pic_lib *
 pic_make_library(pic_state *pic, pic_value name)
diff --git a/src/macro.c b/src/macro.c
index 818e8921..ca84cbfc 100644
--- a/src/macro.c
+++ b/src/macro.c
@@ -11,7 +11,6 @@
 #include "picrin/proc.h"
 #include "picrin/macro.h"
 #include "picrin/lib.h"
-#include "xhash/xhash.h"
 
 static pic_value macroexpand(pic_state *, pic_value, struct pic_senv *);
 static pic_value macroexpand_list(pic_state *, pic_value, struct pic_senv *);
diff --git a/src/state.c b/src/state.c
index d064dc38..a431f0cb 100644
--- a/src/state.c
+++ b/src/state.c
@@ -9,7 +9,6 @@
 #include "picrin/proc.h"
 #include "picrin/macro.h"
 #include "picrin/cont.h"
-#include "xhash/xhash.h"
 
 void pic_init_core(pic_state *);
 
diff --git a/src/symbol.c b/src/symbol.c
index 4ed5ba04..8cd1f62c 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -8,7 +8,6 @@
 #include <assert.h>
 
 #include "picrin.h"
-#include "xhash/xhash.h"
 
 pic_sym
 pic_intern_cstr(pic_state *pic, const char *str)